title: Gastric biopsies: the gap between evidence-based medicine and daily practice in the management of gastric Helicobacter pylori infection.
abstract: BACKGROUND
  Many consider histology to be the gold standard for Helicobacter pylori detection. Because the number and distribution of H pylori organisms vary, particularly in patients taking proton pump inhibitors (PPIs), the American Gastroenterological Association recommends discontinuing PPIs two weeks before endoscopy, and taking biopsies from both the body and antrum.
  
  
  OBJECTIVE
  To assess the influence of clinical practice on the histopathological detection of H pylori infection.
  
  
  METHODS
  Electronic patient records were evaluated for the sites of gastric sampling and PPI use at endoscopy. One hundred fifty cases with biopsies taken from both antrum and body were randomly selected for pathological re-review with special stains. The gastric regions sampled, H pylori distribution and influence of clinical factors on pathological interpretation were assessed.
  
  
  RESULTS
  Between 2005 and 2010, 10,268 biopsies were taken to detect H pylori. Only one region was sampled in 60% of patients (antrum 47%, body 13%). Re-review of biopsies taken from both antrum and body indicated that the correct regions were sampled in only 85 (57%) patients. Of these, 54 were H pylori positive and 96 were H pylori negative. H pylori was present in the antrum in only 15% of the patients and body only in 21%. Of 96 H pylori-negative patients, two were reinterpreted as positive. Forty-seven per cent of patients were taking PPIs at endoscopy, contributing to both false-negative and false-positive diagnoses.
  
  
  CONCLUSIONS
  Despite national and international guidelines for managing H pylori infection, the American Gastroenterological Association guidelines are infrequently adhered to, with PPIs frequently contributing to false diagnosis; sampling one region only increases the likelihood of missing active infection by at least 15%.
authors.forename: Hala
authors.initials: H
authors.lastname: El-Zimaity
authors.forename: Stefano
authors.initials: S
authors.lastname: Serra
authors.forename: Eva
authors.initials: E
authors.lastname: Szentgyorgyi
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Vajpeyi
authors.forename: Amir
authors.initials: A
authors.lastname: Samani
mesh_terms: D001706:Biopsy / Q000379:methods*; D002170:Canada; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D019317:Evidence-Based Medicine; D019983:Guideline Adherence; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D007150:Immunohistochemistry; D017410:Practice Guidelines as Topic; D054328:Proton Pump Inhibitors / Q000627:therapeutic use; D011706:Pyloric Antrum / Q000382:microbiology; D013276:Stomach Ulcer / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology
chemical_list: D054328:Proton Pump Inhibitors